"This deal also confirms speculation over recent days that Glencore had missed out or walked away from acquiring a stake in Bumi, which could have been a coup for Glencore."

Glencore, the commodities and trading giant, was in the running to offer support, Mr Rothschild, Bumi's co-chairman, confirmed last month.

Talks reportedly fell through because lenders were not happy with the structure of the proposal, with Glencore pushing for increased marketing rights over Bumi's coal.

The deal with PT Borneo will keep control of Bumi in Indonesian hands. Bakrie Group and PT Borneo will own the 47.6pc stake through joint vehicles, so Bumi will still have a single blocking shareholder.

The Bakries and the man behind PT Borneo, Samin Tan, have known each other for years, with Mr Tan proving unsuccessful in buying a stake in Bumi back in 2006. The new deal is expected to complete by the end of December.

"The deal is not only about Bakrie," he said. "It's a world-class asset they have here and it's undervalued, too."

The Bakries also faced debt problems in 2008. Investors see value in their political connections, with Aburizal Bakrie, the billionaire head of the family and chairman of Indonesia's Golkar Party, widely expected to run for his country's presidency in 2014.